Electronic device and program storage medium

ABSTRACT

A rotation number calculating section calculates rotation numbers per unit time on the basis of pulse signals, a CPU calculates an accumulated rotation number on the basis of a sum of products of the rotation numbers read at a predetermined time interval and the predetermined time, determines whether the accumulated rotation number exceeds a predetermined threshold value, and gives a warning aiming at urging a user to clean a fan in response to a determination result that the accumulated rotation number exceeds the threshold value.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a an electronic device which is cooled by an air flow generated by rotation of a built-in fan and a program storage medium in which a program executed by the electronic device is stored.

2. Background Art

In a conventional art, when a heat-generating part which generates heat with operation must be mounted in an electronic device, position arrangement of the heat-generating part in the electronic device is schemed, or, if the cooling is not satisfied by scheming the position arrangement, the heat-generating part is cooled by an air flow generated around the heat-generating part.

For example, in an electronic device such as a server or a personal computer, heat generation from an LSI (Large Scale Integration: large-scale integrated circuit) constituting the circuit of a CPU is high. The upper-limit temperature of operation guarantee is not too high, for example, about 95° C. When the LSI strongly generates heat, the operation of the LSI becomes unstable, or the LSI may be damaged by heat to make the electronic device nonusable. Some LSI has a function of degrading the performance to suppress further heat generation when the LSI generates heat to a predetermined temperature. In order to maintain the performance of an LSI and avoid damage, a cooling heat-radiating fin is attached to the LSI, and a fan is arranged in the electronic device. An air flow is generated by the fan to air-cool the LSI.

As such a fan, a fan which blows air out of an electronic device through an exhaust port arranged on the housing of the electronic device or a fan which blows air into an electronic device through an intake port arranged on the housing of the electronic device are known. In addition, an electronic device in which a filter which removes foreign matter such as dust or dirt in air passing through an exhaust port or an intake port is arranged on the exhaust port or the intake port is known.

However, even though such a filter is arranged on the exhaust port or the intake port, if foreign matter is collected on the filter to clog the filter, it is difficult to generate necessary, sufficient air flow in air-cooling by the fan. For this reason, a heat-radiating part is damaged by heat, or the heat-radiating part excessively generates heat, so that the heat-radiating part may take fire. Therefore, it is necessary to clean the filter regularly.

As a technique related to clean the filter is proposed a technique which determines whether an accumulation of operation time for which an electronic device operates exceeds a predetermined threshold value and which gives a warning aiming at urging a user to clean the filter in response to a determination result that the accumulated operation time exceeds the threshold value (for example, see Japanese Patent Application Laid-open No. 3-8407).

As a technique related to cleaning of a filter, for example, the following technique is also proposed. That is, a rate of a change in an in-device temperature measured by changing a rotating speed of the fan in a cleaned filter state is recorded and stored in advance. In this state, when start of detection of filter clogging is designated according to an operation, the rotating speed of the fan is changed, and the in-device temperature is measured. A change rate of the in-device temperature is calculated on the basis of the measured temperature, and the calculated change rate and the change rate of the in-device temperature recorded and stored in advance are compared with each other to determine the necessity of filter cleaning. In response to a determination result that the filter cleaning is necessary, the necessity of the filter cleaning is displayed (for example, see Japanese Patent Application Laid-open No. 2-64329).

According to the technique proposed by Japanese Patent Application Laid-open No. 3-8407, since a filter may be cleaned when a warning aiming at urging a user to clean the filter is given, the user can know time for cleaning without being conscious of the time for cleaning of the filter in use of an electronic device, and the filter can be periodically cleaned.

In this case, as a fan mounted on an electronic device, a fan which repeats rotation and stop depending on a temperature of a heat-generating part and the rotation speed of which changes as needed in rotation is generally used. However, in the technique proposed in Japanese Patent Application Laid-open No. 3-8407, time for cleaning of a filter is determined depending on only operation time of the electronic device. For this reason, the technique can cope with an electronic device in which a fan which always rotates at a predetermined rotating speed is arranged. However, when the technique is applied to an electronic device in which a fan which repeats rotation and stop depending on a temperature of a heat-generating part and the rotating speed of which changes as needed in rotation is arranged, correct time for cleaning of the filter cannot be determined, disadvantageously.

According to the technique proposed by Japanese Patent Application Laid-open No. 2-64329, when detection of filter clogging is designed depending on an operation, a user can be automatically notified of a determination whether the filter must be cleaned. For this reason, even an ordinary user except for a maintenance people can know the necessity of filter cleaning.

However, in the technique proposed in Japanese Patent Application Laid-open No. 2-64329, since determination whether the filter must be cleaned is executed depending on an operation of designating detection of filter clogging, when a state in which the operation is not executed continues for a long period of time, foreign matter is collected on the filter without notifying a user of the necessity of the filter cleaning, and the filter may be clogged. As a result, it is difficult to generate an air flow necessary and sufficient for air-cooling by a fan. A heat-generating part may be damaged by heat, or the heat-generating part may excessively generate heat to take fire.

Furthermore, in the technique proposed by Japanese Patent Application Laid-open No. 2-64329, at an environmental temperature at which an out-of-device temperature (to be referred to as an environmental temperature hereinafter) obtained when a change rate of an in-device temperature recorded and stored in advance is measured and an environmental temperature obtained when a change rate of an in-device temperature calculated depending on an operation are almost equal to each other, the necessity of filter cleaning is correctly determined. However, at an environmental temperature at which the environmental temperatures are considerably different from each other, the change rate calculated depending on the operation is influenced by the difference between the environmental temperatures. In such a determination result using the change rate, the necessity of filter cleaning may not be correctly determined.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above circumstances and provides an electronic device which can correctly and reliably notify a user of time for cleaning of a fan itself arranged on the electronic device or time for cleaning of a filter arranged in an exhaust port or an intake port of the electronic device and a program storage medium in which a program which gives the function to the electronic device is stored.

According to the present invention, there is provided an electronic device in which a fan is built to perform air-cooling by an air flow generated by rotation of the fan, including:

an accumulated rotation number calculating section which calculates an accumulated rotation number of the fan;

a determining section which determines whether the accumulated rotation number calculated by the accumulated rotation number calculating section exceeds a predetermined threshold value; and

a warning section which gives a warning in response to a determination result that the accumulated rotation number exceeds the threshold value, the determination result being obtained by the determination section.

In this case, the fan arranged in the electronic device generally repeats rotation and stop depending on a temperature of a heat-generating part mounted in the electronic device, and a rotating speed of the fan changes as needed in rotation. Therefore, a cumulative amount of foreign matter such as dust or dirt collected on a filter arranged on an exhaust port or an intake port of the electronic device is in proportion to a total volume of an air flow generated by the fan, i.e., the accumulated rotation number of the fan.

The electronic device according to the present invention determines whether the calculated accumulated rotation number of the fan exceeds the predetermined threshold value and gives a warning in response to the determination result that the accumulated rotation number exceeds the threshold value. Therefore, according to the electronic device of the present invention, since the warning is given on the basis of the accumulated rotation number being in proportion to the cumulative amount of foreign matter collected on the fan itself or the filter, time for cleaning of the fan itself or the filter can be correctly and reliably notified.

In this case, in the electronic device according to the present invention,

it is preferable that

“the fan outputs a pulse signal synchronized with rotation of the fan, and

the accumulated rotation number calculating section calculates rotation numbers per unit time at a predetermined time interval and calculates an accumulated rotation number on the basis of a sum of products of the rotation numbers and the predetermined time”.

According to the preferable aspect, it is preferable that the accumulated rotation number is correctly calculated.

The electronic device according to the present invention preferable includes a reset section which resets the accumulated rotation number and the warning in response to a manual operation.

According to the preferable embodiment, the accumulated rotation number and the warning are reset upon completion of cleaning of the fan itself or the filter, so that the warning is preferably given when foreign matter is collected on the cleaned fan itself or the cleaned filter again.

Furthermore, the electronic device according to the present invention includes

“at least one of a power source cord which can be freely connected to an external power source and a detachable battery, and

a reset section which resets the accumulated rotation number and the warning in response to connection of at least one of the power source cord and the battery after both the power source cord and the battery are temporarily disconnected”.

In this case, when the fan itself or the filter is cleaned, the electronic device must be generally decomposed. For this reason, it is very dangerous that a cleaning operation is not started after both the power source cord and the battery are disconnected.

According to the electronic device including the reset device, for example, for example, the warning section gives a warning having a content that “Please turn off the power of the system and clean the fan and the filter while disconnecting the AC adaptor and the battery from the system”. According to the warning, the fan itself or the filter are cleaned to make it possible to safely perform a cleaning operation.

According to the electronic device including the-reset section, in response to reconnection of at least the power source cord and the battery, the accumulated rotation number and the warning are reset. For this reason, it is more preferable that a warning is given when foreign matter is collected on the cleaned fan itself or the cleaned filter without performing an operation except for the reconnection.

The electronic device-according to the present invention is operated as an electronic device having the above functions by executing the program of the present invention. An operation effect obtained by the program of the present invention is as the same as described above.

According to the present invention, there is provided an electronic device which correctly and reliably notifies a user of time for cleaning of a fan itself arranged on the electronic device and time for cleaning of a filter arranged on an exhaust port or an intake port of the electronic device and a storage medium in which a program which gives the function to the electronic device is stored.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an external perspective view showing a first embodiment of a notebook PC to which an embodiment of an electronic device according to the present invention is applied;

FIG. 2 is a software block diagram of the notebook PC according to the first embodiment, the appearance of the notebook PC 10 being shown in FIG. 1;

FIG. 3 is a block diagram of a main part serving to perform an operation of urging a user to clean a on the basis of an accumulated rotation number calculated by the CPU shown in FIG. 2;

FIG. 4 is a flow chart for explaining a flow of operations performed from when the fan arranged in the main-body unit is rotated to when the rotation number per unit time of the fan is temporarily stored;

FIG. 5 is a flow chart for explaining a flow of operations performed from when the rotation numbers per unit time temporarily stored in the temporary storing region are read to when a warning of fan cleaning is given to reset the accumulated rotation number.

FIG. 6 is a diagram showing an example of a warning window displayed on a display screen;

FIG. 7 is a block diagram of main parts which serves to perform a reset operation of the accumulated rotation number and the warning when at least of an AC adaptor and a battery is connected after both the AC adaptor and the battery are temporarily disconnected;

FIG. 8 is a hardware block diagram of the second embodiment of the notebook PC the appearance of which is shown in FIG. 1;

FIG. 9 is a block diagram of main parts serving to perform an operation of giving a warning aiming at urging a user to clean the fan 54 on the basis of an accumulated rotation number calculated by an accumulated rotation number calculating section;

FIG. 10 is a flow chart for explaining a flow of operations performed from when the fan mounted in the main-body unit is rotated to when the accumulated rotation number of the fan is stored in the accumulated rotation number calculating section; and

FIG. 11 is a flowchart for explaining a flow of operations performed from when an accumulated rotation number stored in an EEPROM is read to when a warning to clean a fan is given to reset the accumulated rotation number.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is an external perspective view showing a first embodiment of a notebook personal computer (to be referred to as a “notebook PC” hereinafter) 10 to which an embodiment of the present invention is applied.

The notebook PC 10 shown in FIG. 1 includes a main-body unit 20 and a display section 30. The main-body unit 20 and the display section 30 are connected by a connecting section 40 such that the display section 30 is openable/closable with respect to the main-body unit 20 in a direction of an arrow A-A. In FIG. 1 shows a notebook PC in a state in which the display section 30 is opened with respect to the main-body unit 20.

In the main-body unit 20, on the upper surface, a keyboard 21, a track pad 22, a left-click button 23, a right-click button 24, and an engagement section 25 which engages the display section 30 when the display section 30 is closed are arranged. On side surfaces of the main-body unit 20, a side surface 26 of an optical disk drive on which an optical disk such as a CD or a DVD is loaded to access the optical disk and an opening/closing lid 27 of an MO drive on which an MO is loaded to access the MO are exposed to the outer surface of main-body unit 20.

In the display section 30 of the notebook PC 10, a large display screen 31 spreads on the front surface. A fastening section 32 which is engaged with the engagement section 25 of the main-body unit 20 when the display section 30 is closed is arranged above the display screen 31.

FIG. 2 is a hardware block diagram of the notebook PC 10 according to the first embodiment, the appearance of the notebook PC 10 being shown in FIG. 1.

In the hardware block diagram shown in FIG. 2, a hard disk controller 111, an keyboard controller 115, an optical disk drive 113, a track pad controller 114, a keyboard controller 115, a display controller 116, a fan control section 117, a rotation number calculating section 118, a CPU 119, a main memory 120, an EEPROM 121, and a power source management section 122 are shown. These components are connected to each other by a bus 110.

The hard disk controller 111 is a constituent element which serves to access a hard disk 51 built in the notebook PC 10. In the hard disk 51, an OS (operating system) executed in the notebook PC 10 and various application programs are stored.

The MO drive 112 serves to access an MO 52 loaded from the opening/closing lid 27 shown in FIG. 1. The optical disk drive 113 serves to access a loaded optical disk 53.

The track pad controller 114, the keyboard controller 115, and the display controller 116 serve to detect an operation of a track pad 22 (including the left-click button 23 and the right-click button 24), to detect an operation of the keyboard 21, and to control screen display on the display screen 31.

The fan control section 117 serves to control rotation of the fan 54 arranged in the main-body unit 20, and the rotation number calculating section 118 serves to calculate a rotation number per unit time of the fan 54. The rotation number calculating section 118 has a temporary storing region 1181 which temporarily stores the calculated rotation number per unit time.

Furthermore, the CPU 119 serves to read various programs stored in the hard disk 51, to develop the programs on the main memory 120, and to execute the various programs developed on the main memory 120. The CPU 119 serves to read a rotation number per unit time temporarily stored in the temporary storing region 1181 in the rotation number calculating section 118 and to calculate an accumulated rotation number. The CPU 119 is a circuit part with high heat generation in operation. The CPU 119 is air-cooled as needed such that an air flow is generated around the CPU 119 by the fan 54. The combination of the CPU 119 and the rotation number calculating section 118 corresponds to an example of the accumulated rotation number calculating section according to the present invention. The notebook PC 10 gives a warning on the basis of the accumulated rotation number calculated by the CPU 119 to urge a user to clean the fan 54. Details related to the warning of the fan cleaning will be described later.

In the main memory 120, the programs are developed as described above, and various data in execution of the programs in the CPU 119 are stored.

In the EEPROM 121, the accumulated rotation number calculated by the CPU 119 is written by the CPU 119 as needed and overwritten in a nonvolatile manner. In the EEPROM 121, a predetermined threshold value is stored in advance.

The power source management section 122 manages a power source function of the notebook PC 10 and monitors a charging state of a battery 55 detachably connected to the main-body unit 20 and input power from the AC adaptor 56 which can be freely connected to an external power source to control selection of a power source or a charging state of the battery 55. The battery 55 corresponds to an example of the battery according to the present invention, and the AC adaptor 56 corresponds to an example of the power source cord according to the present invention.

In this case, a characteristic feature of an embodiment of the present invention in the notebook PC 10 shown in FIGS. 1 and 2 is an operation of urging a user to clean the fan 54 on the basis of the accumulated rotation number calculated by the CPU 119 shown in FIG. 2. The operation will be further concretely described below in detail.

FIG. 3 is a block diagram of a main part serving to perform an operation of urging a user to clean the fan 54 on the basis of the accumulated rotation number calculated by the CPU 119 shown in FIG. 2.

In FIG. 3, of the parts built in the main-body unit 20, the fan 54, the fan control section 117, the rotation number calculating section 118, the temporary storing region 1181, the CPU 119, and the EEPROM 121 are shown. A filter 541 which removes foreign matter such as dirt or dust in air passing through an exhaust port or an intake port (not shown) is arranged in the exhaust port or the intake port.

The fan 54 repeats rotation and stop depending on a temperature of the CPU 119. The rotation of the fan 54 is controlled by the fan control section 117 such that the rotation number changes in rotation as needed. The fan 54 outputs a pulse signal (2 pulses a rotation) synchronized with the rotation of the fan 54 to the rotation number calculating section 118.

The rotation number calculating section 118 calculates rotation numbers per unit time at a predetermined time interval on the basis of the pulse signal output from the fan 54 and temporarily stores the calculated rotation numbers per unit time in the temporary storing region 1181 in the rotation number calculating section 118.

The CPU 119, as described above, is a circuit part with high heat generation in operation. The CPU 119 most requires to be cooled since the upper-limit temperature of the operation guarantee is about 95° C. For this reason, the fan 54 is arranged at such a position that the CPU 119 is concentrically cooled.

The CPU 119 reads rotation numbers per unit time temporarily stored in the temporary storing region 1181 in the rotation number calculating section 118 at predetermined time intervals. On the basis of a sum of products of the rotation numbers and the predetermined time, an accumulated rotation number is calculated.

The CPU 119 writes the accumulated rotation number calculated as described above on the EEPROM 121 as needed and overwritten in a nonvolatile manner.

The CPU 119 determines whether the accumulated rotation number stored in the EEPROM 121 exceeds a predetermined threshold value stored in the EEPROM 121 in advance. The CPU 119 corresponds to an example of a deciding section according to the present invention.

Furthermore, in response to a decision result that the accumulated rotation number exceeds the threshold value, the CPU 119 gives a designation signal according to a designation which displays a warning aiming at to urging a user to clean the fan 54 on the display screen 31 to the display controller 116 (see FIG. 2). The designation signal is given to the display controller 116, the display controller 116 displays the warning aiming at urging a user to clean the fan 54 on the display screen 31. The CPU 119, the display controller 116, and the display screen 31 corresponds to an example of the warning section according to the present invention.

FIG. 4 is a flow chart for explaining a flow of operations performed from when the fan 54 arranged in the main-body unit 20 is rotated to when the rotation number per unit time of the fan 54 is temporarily stored in the rotation number calculating section 118.

The operations described in the flow charts shown in FIG. 4 are started such that the notebook PC 10 to which the battery 55 is connected and the AC adaptor 56 connected to an external power source is connected as needed is driven, the CPU 119 generates a heat at a predetermined temperature or higher, and the fan 54 rotationally controlled by the fan control section 117 depending on the temperature of the CPU 119 is rotated.

A pulse signal (2 pulses a rotation) synchronized with the rotation of the fan 54 is input (step S11).

On the basis of the pulse signal input in step S11, rotation numbers per unit time are calculated at a predetermined time interval (step S12).

The rotation numbers per time unit calculated in step S12 are temporarily stored in the temporary storing region 1181 in the rotation number calculating section 118 (step S13).

Hereinafter, the operations in steps S11 to S13 are repeatedly executed.

FIG. 5 is a flow chart for explaining a flow of operations performed from when the rotation numbers per unit time temporarily stored in the temporary storing region 1181 are read to when a warning of fan cleaning is given to reset the accumulated rotation number.

The operations explained in the flow chart shown in FIG. 5 are started by accessing the temporary storing region 1181 in the rotation number calculating section 118 at a predetermined time interval.

The rotation numbers per unit time temporarily stored in the temporary storing region 1181 are read at a predetermined interval (step S21).

An accumulated rotation number is calculated on the basis of a sum of products of the rotation numbers read in step S21 and the predetermined time (step S22).

The accumulated rotation number calculated in step S22 is written in the EEPROM 121 as needed and overwritten in the EEPROM 121 in a nonvolatile manner (step S23).

It is determined whether the accumulated rotation number stored in the EEPROM 121 in step S104 exceeds a predetermined threshold value stored in the EEPROM 121 in advance (step S24).

When the result obtained by the determination in step S105 is a determination result that the accumulated rotation number exceeds the threshold value (step S24: Yes), a designation signal according to the designation for displaying a warning aiming at to urging a user to clean the fan 54 on the display screen 31 is given to the display controller 116 (see FIG. 2) in response to the decision result, and displays a warning window 311 (will be described later) on the display screen 31 (step S25).

When the determination result obtained in step S105 is a decision result that the accumulated rotation number is less than the threshold value (step S24: No), the operations shown in the flow chart are ended.

FIG. 6 is a diagram showing an example of the warning window 311 displayed on the display screen 31.

When the designation signal is given to the display controller 116 by the CPU 119 in step S25 (see FIG. 5), as shown in FIG. 6, the warning window 311 such as “Please turn off the power of the system and clean the fan and the filter while temporarily disconnecting the AC adaptor and the battery from the system” to urge a user to clean the fan 54 is on the display screen 31.

When the fan 54 and the filter 541 are to be cleaned, the electronic device must be discomposed, it is very dangerous to start a cleaning operation without temporarily disconnecting both the AC adaptor 56 and the battery 55. Therefore, the warning having the contents displayed on the warning window 311 shown in FIG. 6 is given, and the fan 54 and the filter 541 are cleaned according to the warning, so that the cleaning operation can be safely performed.

Returning to FIG. 5, the explanation of the flow chart is continued.

After the warning window 311 which urges a user to clean the fan 54 is displayed on the display screen 31 in step S25, in response to a connection of at least one of the AC adaptor 56 and the battery 55 after both the AC adaptor 56 and the battery 55 are disconnected, the accumulated rotation number stored in the EEPROM 121 is reset, and a designation signal according to a designation for closing the warning window 311 (see FIG. 6) displayed on the display screen 31 in step S25 is given to the display controller 116 (see FIG. 2) to close the warning window 311 (see FIG. 6) (step S26).

FIG. 7 is a block diagram of main parts which serves to perform a reset operation of the accumulated rotation number and the warning when at least of the AC adaptor 56 and the battery 55 is connected after both the AC adaptor 56 and the battery 55 are temporarily disconnected.

In FIG. 7, of the parts built in the main-body unit 20, the AC adaptor 56, the battery 55, a PMU_VCC 1221, a PMU 1222, and the CPU 119 are shown. A combination of the PMU_VCC 1221 and the PMU 1222 corresponds to the power source management section 122 shown in FIG. 2.

To the PMU_VCC 1221, power is always supplied from the AC adaptor 56 or the battery 55 electrically connected to the notebook PC 10 regardless of the ON/OFF state of the power switch of the notebook PC 10.

The PMU 1222 is to manage a power source function of the notebook PC 10. The power source management section 122 monitors a charging state of the battery 55 detachably connected to the main-body unit 20 or input power from the AC adaptor 56 which can be connected to an external power source to control selection of power source or a charging state of the battery 55. Since power is supplied to the PMU 1222 from the PMU_VCC 1221 to which power is always supplied from the AC adaptor 56 or the battery 55, when the AC adaptor 56 or the battery 55 is electrically connected to the notebook PC 10, the notebook PC 10 always operates regardless of the ON/OFF state of the power switch of the notebook PC 10.

Therefore, when both the AC adaptor 56 and the battery 55 are disconnected in step S26 (see FIG. 5), with power off to the PMU_VCC 1221, power to the PMU 1222 operated by power from the PMU_VCC 1221 is stopped.

When at least one of the AC adaptor 56 and the battery 55 is connected after both the AC adaptor 56 and the battery 55 are temporarily disconnected in step S26 (see FIG. 5), power is supplied from the connected AC adaptor 56 or the connected battery 55 to the PMU_VCC 1221, and power is supplied from the PMU_VCC 1221 to the PMU 1222. The PMU 1222 recognizes that the AC adaptor 56 or the battery 55 is connected to the notebook PC 10 again.

When the recognition is performed by the PMU 1222, the CPU 119 resets the accumulated rotation number stored in the EEPROM 121 in step S23 (see FIG. 5), and a designation signal according to a designation for closing the warning window 311 (see FIG. 6) displayed on the display screen 31 in step S25 (see FIG. 5) is given to the display controller 116 (see FIG. 2) to close the warning window 311 (see FIG. 6). The CPU 119 corresponds to an example of the reset section according to the present invention.

As described above, in the notebook PC 10 according to the first embodiment, the rotation number calculating section 118 calculates rotation numbers per unit time on the basis of pulse signals, the CPU 119 calculates an accumulated rotation number on the basis of a sum of products of the rotation numbers read at a predetermined time interval and the predetermined time, determines whether the accumulated rotation number exceeds a predetermined threshold value, and gives a warning aiming at urging a user to clean the fan 54 in response to the determination result that the accumulated rotation number exceeds the threshold value. Therefore, in the notebook PC 10 according to the first embodiment, the warning is performed on the basis of the accumulated rotation number which is in proportion to a cumulative amount of foreign matter collected on the fan 54 or the filter 541, so that time for cleaning the fan 54 or the filter 541 is correctly and reliably notified.

In the notebook PC 10 according to the first embodiment, in response to reconnection of at least one of the AC adaptor 56 and the battery 55, the accumulated rotation number and the warning are reset. For this reason, without performing an operation except for the reconnection, a warning is given when foreign matter is collected on the cleaned fan 54 or the cleaned filter 541 again. For this reason, the notebook PC 10 is more preferable.

A second embodiment of the present invention will be described below.

Since the second embodiment (will be described below) almost has the same configuration as that of the first embodiment. For this reason, attention is paid to different points between the second embodiment and the first embodiment. The same reference numerals as in the first embodiment denote the same parts in the second embodiment, and a description thereof is omitted.

FIG. 8 is a hardware block diagram of the second embodiment of the notebook PC 10 the appearance of which is shown in FIG. 1.

In the hardware block diagram shown in FIG. 8, a hard disk controller 111, an MO drive 112, an optical disk drive 113, a track pad controller 114, a keyboard controller 115, a display controller 116, a fan control section 117, an accumulated rotation number calculating section 218, a CPU 119, a main memory 120, and a power source management section 122. These components are connected to each other by a bus 110.

The accumulated rotation number calculating section 218 serves to calculate an accumulated rotation number of the fan 54 arranged in the main-body unit 20. The accumulated rotation number calculating section 218 corresponds to an example of the accumulated rotation number calculating section according to the present invention. The accumulated rotation number calculating section 218 has an EEPROM 221 in which the calculated accumulated rotation number is written as needed and overwritten in a nonvolatile manner. In the EEPROM 221, a predetermined threshold value is stored in advance. The notebook PC 10 also gives a warning aiming at urging a user to clean the fan 54 on the basis of the accumulated rotation number calculated by the accumulated rotation number calculating section 218. An explanation about the warning of the fan cleaning will be described later.

Furthermore, various programs stored in a hard disk 51 are read and developed on the main memory, and the CPU 119 serves to execute the various programs developed on the main memory 120.

In the notebook PC 10 shown in FIGS. 1 and 8, a characteristic feature of an embodiment of the present invention is an operation in which a warning aiming at urging a user to clean the fan 54 on the basis of the accumulated rotation number calculated by the accumulated rotation number calculating section 218 shown in FIG. 8. The operation will be described below in more detail.

FIG. 9 is a block diagram of main parts serving to perform an operation of giving a warning aiming at urging a user to clean the fan 54 on the basis of the accumulated rotation number calculated by the accumulated rotation number calculating section 218.

In FIG. 9, of the parts built in the main-body unit 20, the fan 54, a filter 541, the fan control section 117, the accumulated rotation number calculating section 218, the EEPROM 221, and the CPU 119 are shown.

The accumulated rotation number calculating section 218 calculates rotation numbers per unit time at a predetermined time interval on the basis of pulse signals output from the fan 54 and calculates an accumulated rotation number on the basis of a sum of products of the rotation numbers and the predetermined time.

The accumulated rotation number calculating section 218 writes the calculated accumulated rotation number in the EEPROM 221 in the accumulated rotation number calculating section 218 as needed. The calculated accumulated rotation number is overwritten and stored in a nonvolatile manner. A predetermined threshold value is set and stored in the EEPROM 221 through a BUS in advance.

The CPU 119 monitors and determines as needed by an Alert output whether the accumulated rotation number calculated by the accumulated rotation number calculating section 218 and stored in the EEPROM 221 exceeds the predetermined threshold value stored in the EEPROM 221 in advance. The CPU 119 corresponds to an example of the determining section according to the present invention.

FIG. 10 is a flowchart for explaining a flow of operations performed from when the fan 54 mounted in the main-body unit 20 is rotated to when the accumulated rotation number of the fan 54 is stored in the accumulated rotation number calculating section 218.

The operations explained in the flow chart shown in FIG. 10 is started so that the notebook PC 10 to which the battery 55 is connected and the AC adaptor 56 connected to an external power source is connected as needed is driven, the CPU 119 generates a heat at a predetermined temperature or higher, and the fan 54 rotationally controlled by the fan control section 117 depending on the temperature of the CPU 119 is rotated.

A pulse signal (2 pulses a rotation) synchronized with the rotation of the fan 54 is input (step S31).

On the basis of the pulse signal input in step S31, rotation numbers per unit time are calculated at a predetermined time interval (step S32).

An accumulated rotation number is calculated on the basis of a sum of products of the rotation numbers per unit time calculated in step S32 and the predetermined time (step S33)

The accumulated rotation number calculated in step S33 is written in the EEPROM 221 in the accumulated rotation number calculating section 218 as needed and overwritten and stored in a nonvolatile manner (step S34).

Hereinafter, the operations in steps S31 to S34 are repeatedly executed.

FIG. 11 is a flow chart for explaining a flow of operations performed from when the accumulated rotation number stored in the EEPROM 221 is read to when a warning to clean a fan is given to reset the accumulated rotation number in the CPU 119.

The operations explained in the flow chart shown in FIG. 11 are started by accessing the EEPROM 221 in the accumulated rotation number calculating section 218 at a predetermined time interval.

The accumulated rotation number stored in the EEPROM 221 is read at a predetermined time interval (step S41).

It is determined whether the accumulated rotation number read in step S41 exceeds a predetermined threshold value stored in the EEPROM 221 in advance (step S42).

When the determination result obtained by the determination in step S42 is a determination result that the accumulated rotation number exceeds the threshold value (step S42: Yes), a designation signal according to a designation for displaying a warning aiming at urging a user to clean the fan 54 on the display screen 31 is given to the display controller 116 (see FIG. 8) in response to the decision result, and displays a warning window 311 (see FIG. 6) is displayed on the display screen 31 (step S43)

When the determination result obtained in step S42 is a determination result that the accumulated rotation number is less than the threshold value (step S42: No), in response to the determination result, the operations shown in the flow chart are ended.

After the warning window 311 ( see FIG.6 ) which urges a user to clean the fan 54 is displayed on the display screen 31 in step S43, in response to a connection of at least one of the AC adaptor 56 and the battery 55 after both the AC adaptor 56 and the battery 55 are disconnected, the accumulated rotation number stored in the EEPROM 221 is reset, and a designation signal according to a designation for closing the warning window 311 (see FIG. 6) displayed on the display screen 31 is given to the display controller 116 (see FIG. 8) to close the warning window 311 (see FIG. 6) (step S44).

As described above, the notebook PC 10 according to the second embodiment determines whether the accumulated rotation number of the fan 54 calculated by the accumulated rotation number calculating section 218 exceeds the predetermined threshold value and gives a warning aiming at urging a user to clean the fan 54 in response to the determination result that the accumulated rotation number exceeds the threshold value. According to the notebook PC 10 of the second embodiment, a warning is given on the basis of the accumulated rotation number which is in proportion to a cumulative amount of foreign matter collected on the fan 54 or the filter 541. For this reason, time for cleaning the fan 54 or the filter 541 is correctly and reliably notified.

In each of the embodiments, the example in which a notebook PC is used as an electronic device according to the present invention is described. However, the present invention is not limited to the notebook PC. The present invention can be applied to any type of electronic device in which air-cooling is performed by an air flow generated by rotation of a fan built in the electronic device.

In each of the embodiments, the example in which the warning section displays an image expressing a warning on a display screen to perform a warning is described. However, the warning section according to the present invention is not limited to the warning section described here. For example, a warning section or the like which gives a warning by a warning lamp or warning sound may be used.

In each of the embodiments, the example, the power source cord according to the present invention is an AC adaptor is explained. However, the power source cord according to the present invention is not limited to the power source cord described here. Any power source cord which can be connected to an external power source may be used.

In each of the embodiments, the example in which the reset section according to the present invention resets an accumulated rotation number and a warning in response to connection of at least one of the AC adaptor and the battery after both the AC adaptor and the battery are disconnected is explained. However, the reset section according to the present invention is not limited to the reset section described here. For example, a reset section which resets the accumulated rotation number and the warning in response to a manual operation such as a keyboard operation may be used. 

1. An electronic device with a fan built therein to perform air-cooling by an air flow generated by rotation of the fan, comprising: an accumulated rotation number calculating section which calculates an accumulated rotation number of the fan; a determining section which determines whether the accumulated rotation number calculated by the accumulated rotation number calculating section exceeds a predetermined threshold value; and a warning section which gives a warning in response to a determination result that the accumulated rotation number exceeds the threshold value, the determination result being obtained by the determination section.
 2. The electronic device according to claim 1, wherein the fan outputs a pulse signal synchronized with rotation of the fan, and the accumulated rotation number calculating section calculates rotation numbers per unit time at a predetermined time interval and calculates an accumulated rotation number on the basis of a sum of products of the rotation numbers and the predetermined time.
 3. The electronic device according to claim 1, comprising: a reset section which resets the accumulated rotation number and the warning in response to a manual operation.
 4. The electronic device according to claim 1, comprising: at least one of a power source cord which can be freely connected to an external power source and a detachable battery; and a reset section which resets the accumulated rotation number and the warning in response to connection of at least one of the power source cord and the battery after both the power source cord and the battery are temporarily disconnected.
 5. A program storage medium in which a program executed in an electronic apparatus with a fan built therein to perform air-cooling by an air flow generated by rotation of the fan is stored, the program storage medium storing the program which causes the electronic apparatus to operate as an apparatus comprising: an accumulated rotation number calculating section which calculates an accumulated rotation number of the fan; a determining section which determines whether the accumulated rotation number calculated by the accumulated rotation number calculation section exceeds a predetermined threshold value; and a warning section which gives a warning in response to a determination result that the accumulated rotation number exceeds the predetermined threshold value, the determination result being obtained by the determining section. 